[vsnet-grb-info 22194] GRB 190427A: Fermi GBM detection
GCN Circulars
gcncirc at capella2.gsfc.nasa.gov
Sun Apr 28 02:15:40 JST 2019
TITLE: GCN CIRCULAR
NUMBER: 24293
SUBJECT: GRB 190427A: Fermi GBM detection
DATE: 19/04/27 17:14:36 GMT
FROM: Christian Malacaria at NASA-MSFC/USRA <cmalacaria at usra.edu>
C. Malacaria (NASA-MSFC/USRA), A. von Kienlin (MPE)
and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 04:34:15.08 UT on 27 04 2019, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 190427A (trigger 578032460 / 190427190).
The event was also detected by the Swift/BAT
(Tohuvavohu et al. 2019, GCN 24261)
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time
is 106 degrees.
The GBM light curve consists of a dominant pulse with following
structure and a duration (T90) of about 0.37 s (50-300 keV).
The time-averaged spectrum from T0-0.064 s to T0+0.384 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.05 +/- 0.18 and
the cutoff energy, parameterized as Epeak, is 246.40 +/- 78.20 keV.
The event fluence (10-1000 keV) in this time interval is
(4.855 +/- 0.717)E-07 erg/cm^2. The 64-msec peak photon flux measured
starting from T0+0.0 s in the 10-1000 keV band
is 18.8 +/- 1.1 ph/s/cm^2."
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info,
please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/
More information about the vsnet-grb-info
mailing list